There are more than 7,000 kinds of flavored e-cigarette liquids available for purchase. These products, which are not regulated by the U.S. Food and Drug Administration (FDA) are popular and flying off the shelves. However, a recent study found more than 75 percent of the flavored e-cigarettes and refill liquids tested positive for diacetyl, a flavoring chemical that is linked to obliterative bronchiolitis, a serious lung disease where the smallest airways of the lungs become scarred and restricted. It can only be cured by lung transplant.
When researchers at Harvard T.H. Chan School of Public Health found the flavoring chemical in the e-cigarette liquids, they also found harmful compounds in other flavors — acetoin, and 2,3-pentanedione (a diacetyl substitute) — which are also considered to be “high priority,” meaning they are a workplace hazard.
Obliterative bronchiolitis is better known as “popcorn lung” because several workers in a Missouri microwave popcorn plant developed the lung disease in 2000 after inhaling diacetyl on the job. The chemical is used in microwave popcorn to mimic the flavor of butter.
According to Joseph Allen, study lead author and Assistant Professor of Exposure Assessment Science, the study of harmful inhaled chemicals such as diacetyl started with the “popcorn lung” incident 16 years ago.
David Christiani, study co-author and Elkan Blout Professor of Environmental Genetics, added, “Since most of the health concerns about e-cigarettes have focused on nicotine, there is still much we do not know about e-cigarettes. In addition to containing varying levels of the addictive substance nicotine, they also contain other cancer-causing chemicals, such as formaldehyde, and as our study shows, flavoring chemicals that can cause lung damage.”